Being resilient

In how many ways can you fit all three pieces together to make shapes with line symmetry?

A game for two people, or play online. Given a target number, say 23, and a range of numbers to choose from, say 1-4, players take it in turns to add to the running total to hit their target.

How many moves does it take to swap over some red and blue frogs? Do you have a method?

Imagine you have an unlimited number of four types of triangle. How many different tetrahedra can you make?

Arrange the four number cards on the grid, according to the rules, to make a diagonal, vertical or horizontal line.

The items in the shopping basket add and multiply to give the same amount. What could their prices be?

Choose four different digits from 1-9 and put one in each box so that the resulting four two-digit numbers add to a total of 100.

On a digital 24 hour clock, at certain times, all the digits are consecutive. How many times like this are there between midnight and 7 a.m.?

Chris and Jo put two red and four blue ribbons in a box. They each pick a ribbon from the box without looking. Jo wins if the two ribbons are the same colour. Is the game fair?

Play the divisibility game to create numbers in which the first two digits make a number divisible by 2, the first three digits make a number divisible by 3...